Glucan defective mutants of Streptococcus mutans strains will be compared for their extracellular enzymatic activities utilizing incorporation of labeled precursors into glucans in situ after thin layer gel isoelectric focusing is performed. The isoelectric profiles of the enzymes will be determined at the same time. The mutants will also be compared to those produced by the parent strains and an attempt to correlate enzymatic activities with altered morphological phenotypes will be made. Plaque defective mutants will also be studied for their ability to restore wild type phenotypes when grown in mixed cultures.